On 6/12/19 5:33 AM, Richard Biener wrote:
On Wed, Jun 12, 2019 at 1:57 AM Martin Sebor <mse...@gmail.com> wrote:
On 6/11/19 3:02 PM, Aldy Hernandez wrote:
On 6/11/19 12:52 PM, Martin Sebor wrote:
On 6/11/19 10:26 AM, Aldy Hernandez wrote:
On 6/11/19 12:17 PM, Martin Sebor wrote:
On 6/11/19 9:05 AM, Aldy Hernandez wrote:
On 6/11/19 9:45 AM, Richard Biener wrote:
On Tue, Jun 11, 2019 at 12:40 PM Aldy Hernandez <al...@redhat.com>
wrote:
This patch cleans up the various contains, may_contain, and
value_inside_range variants we have throughout, in favor of one--
contains_p. There should be no changes in functionality.
I have added a note to range_includes_zero_p, perhaps as a personal
question than anything else. This function was/is returning true
for
UNDEFINED. From a semantic sense, that doesn't make sense.
UNDEFINED
is really the empty set. Is the functionality wrong, or should
we call
this function something else? Either way, I'm fine removing the
comment
but I'm genuinely curious.
So this affects for example this hunk:
- if (vr && !range_includes_p (vr, 1))
+ if (vr && (!vr->contains_p (build_one_cst (TREE_TYPE (name)))
+ && !vr->undefined_p ()))
{
I think it's arbitrary how we compute X in UNDEFINED and I'm fine
with changing the affected predicates to return false. This means
not testing for !vr->undefined_p here.
Excellent.
Note I very much dislike the build_one_cst () call here so please
provide an overload hiding this.
Good idea. I love it.
Not sure why you keep range_includes_zero_p.
I wasn't sure if there was some subtle reason why we were including
undefined.
OK pending tests?
Should the second overload:
+ bool contains_p (tree) const;
+ bool contains_p (int) const;
take something like HOST_WIDE_INT or even one of those poly_ints
like build_int_cst does? (With the former, contains_p (0) will
likely be ambiguous since 0 is int and HOST_WIDE_INT is long).
We have a type, so there should be no confusion:
+ return contains_p (build_int_cst (type (), val));
(UNDEFINED and VARYING don't have a type, so they are special cased
prior).
I didn't mean the overloads are confusing, just that there the one
that takes an int doesn't make it possible to test whether a value
outside the range of an int is in the range. For example, in
the call
contains_p (SIZE_MAX)
the argument will get sliced (and trigger a -Woverflow). One will
need to go back to the more verbose way of calling it.
The int version is not really meant to pass anything but simple
constants. For anything fancy, one should really be using the tree
version. But I can certainly change the argument to HOST_WIDE_INT if
preferred.
Changing the argument type to HOST_WIDE_INT would avoid the slicing
and warning but then make contains_p (0) ambiguous because 0 isn't
a perfect match for either void* or long (so it requires a conversion).
Just a plain 0 will match the int version, instead of the tree version,
right? Nobody should be passing NULL to the tree version, so that seems
like a non-issue.
Right, NULL isn't a problem, but I would expect any integer to work
(I thought that's what Richard was asking for) So my suggestion was
to have contains_p() a poly_int64 and provide just as robust an API
as build_int_cst. The argument ends up converted to the poly_int64
anyway when it's passed to the latter. I.e., why not define
contains_p simply like this:
bool
value_range_base::contains_p (poly_int64 val) const
{
if (varying_p ())
return true;
if (undefined_p ())
return false;
return contains_p (build_int_cst (type (), val));
}
I agree that plain 'int' is bad. Given we currently store
INTEGER_CSTs only (and not POLY_INT_CSTs) a
widest_int argument should be fine. Note widest
because when interpreted signed all unsigned values
fit.
The existing contains_p check is also a bit fishy
for the cases TREE_TYPE of the value has a
value-range not covered in the value-ranges type...
I guess it could do
if (!int_fits_type_p (val, this->type ())
return false;
but that changes existing behavior which happily
throws different sign constants into tree_int_cst_lt
for example... Do we want to allow non-INTEGER_CST
val arguments at all? That is, you make contains_p
return a bool and say "yes" when we couldn't really
decide. This is why previously it was named
may_contain_p (and we didn't have must_contain_p).
I think making the result explicitely clear is a must
since contains_p reads like !contains_p means
it does _not_ contain. So, either change back the
name (and provide the must variant)
or make it return the tri-state from value_inside_range.
The only reason I added the int overload was because you didn't like the
build_one_cst call. However, if we make it HOST_WIDE_INT or even
widest_int, it will cause a conflict resolution with the tree version.
I think it's best we only provide a tree version, and make due with the
one call to build_one_cst. There is still the range_includes_zero_p()
convenience function that takes care of the common case.
I see what you mean with the may/must problem. We don't have that
problem in the ranger because we only deal with constants, and there is
never ambiguity. Since we don't have any consumers of must_contain_p
yet, let's leave this bit for later discussion when it's actually needed.
What I propose then is a general clean up of may_contain_p, making
value_inside_range a member function that deals with the range in THIS.
We can remove value_inside_range, as it's only used from the one
build_on-cst place, and range_includes_zero_p (which I've adjusted
accordingly).
Note. I've changed existing functionality to so that may_contains_p
(and range_includes_zero_p accordingly) returns FALSE for VR_UNDEFINED.
AFAIU, VR_UNDEFINED is the empty set, so we absolutely know it's not
inside the range. I've tested my patch both with and without this
VR_UNDEFINED changelet, and there are no regressions.
With this cleanup, particularly with rewriting may_contain_p in terms of
the now value_inside_range method, we can later provide must_contain_p
when needed with just:
bool
value_range_base::must_contain_p (tree val) const
{
return value_inside_range (val) == 1;
}
OK?
gcc/
* gimple-loop-versioning.cc (prune_loop_conditions): Use
may_contain_p.
* tree-vrp (value_range_base::may_contain_p): Call into
value_inside_range.
(value_inside_range): Make private inside value_range_base class.
Take min/max from *this.
(range_includes_p): Remove.
* tree-vrp.h (value_range_base): Add value_inside_range.
(range_includes_p): Remove.
(range_includes_zero_p): Call may_contain_p.
* vr-values.c (compare_range_with_value): Same.
diff --git a/gcc/gimple-loop-versioning.cc b/gcc/gimple-loop-versioning.cc
index 2f7cda9c8cb..fe273001423 100644
--- a/gcc/gimple-loop-versioning.cc
+++ b/gcc/gimple-loop-versioning.cc
@@ -1488,7 +1488,7 @@ loop_versioning::prune_loop_conditions (struct loop *loop, vr_values *vrs)
{
tree name = ssa_name (i);
value_range *vr = vrs->get_value_range (name);
- if (vr && !range_includes_p (vr, 1))
+ if (vr && !vr->may_contain_p (build_one_cst (TREE_TYPE (name))))
{
if (dump_enabled_p ())
dump_printf_loc (MSG_NOTE, find_loop_location (loop),
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index 065152aca3b..dc7f825efc8 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -287,18 +287,7 @@ value_range::set_varying ()
bool
value_range_base::may_contain_p (tree val) const
{
- if (varying_p ())
- return true;
-
- if (undefined_p ())
- return true;
-
- if (m_kind == VR_ANTI_RANGE)
- {
- int res = value_inside_range (val, min (), max ());
- return res == 0 || res == -2;
- }
- return value_inside_range (val, min (), max ()) != 0;
+ return value_inside_range (val) != 0;
}
void
@@ -1118,40 +1107,38 @@ compare_values (tree val1, tree val2)
}
-/* Return 1 if VAL is inside value range MIN <= VAL <= MAX,
- 0 if VAL is not inside [MIN, MAX],
+/* Return 1 if VAL is inside value range.
+ 0 if VAL is not inside value range.
-2 if we cannot tell either way.
Benchmark compile/20001226-1.c compilation time after changing this
function. */
int
-value_inside_range (tree val, tree min, tree max)
+value_range_base::value_inside_range (tree val) const
{
int cmp1, cmp2;
- cmp1 = operand_less_p (val, min);
+ if (varying_p ())
+ return 1;
+
+ if (undefined_p ())
+ return 0;
+
+ cmp1 = operand_less_p (val, m_min);
if (cmp1 == -2)
return -2;
if (cmp1 == 1)
- return 0;
+ return m_kind != VR_RANGE;
- cmp2 = operand_less_p (max, val);
+ cmp2 = operand_less_p (m_max, val);
if (cmp2 == -2)
return -2;
- return !cmp2;
-}
-
-
-/* Return TRUE if *VR includes the value X. */
-
-bool
-range_includes_p (const value_range_base *vr, HOST_WIDE_INT x)
-{
- if (vr->varying_p () || vr->undefined_p ())
- return true;
- return vr->may_contain_p (build_int_cst (vr->type (), x));
+ if (m_kind == VR_RANGE)
+ return !cmp2;
+ else
+ return !!cmp2;
}
/* Value range wrapper for wide_int_range_set_zero_nonzero_bits.
diff --git a/gcc/tree-vrp.h b/gcc/tree-vrp.h
index 62d72868708..4ec974f5fdb 100644
--- a/gcc/tree-vrp.h
+++ b/gcc/tree-vrp.h
@@ -97,6 +97,9 @@ protected:
friend void gt_ggc_mx (value_range_base *&);
friend void gt_pch_nx (value_range_base &);
friend void gt_pch_nx (value_range_base *, gt_pointer_operator, void *);
+
+private:
+ int value_inside_range (tree) const;
};
/* Note value_range cannot currently be used with GC memory, only
@@ -254,7 +257,6 @@ struct assert_info
extern void register_edge_assert_for (tree, edge, enum tree_code,
tree, tree, vec<assert_info> &);
extern bool stmt_interesting_for_vrp (gimple *);
-extern bool range_includes_p (const value_range_base *, HOST_WIDE_INT);
extern bool infer_value_range (gimple *, tree, tree_code *, tree *);
extern bool vrp_bitmap_equal_p (const_bitmap, const_bitmap);
@@ -267,7 +269,6 @@ extern int compare_values_warnv (tree, tree, bool *);
extern int operand_less_p (tree, tree);
extern bool vrp_val_is_min (const_tree);
extern bool vrp_val_is_max (const_tree);
-extern int value_inside_range (tree, tree, tree);
extern tree vrp_val_min (const_tree);
extern tree vrp_val_max (const_tree);
@@ -300,7 +301,13 @@ extern value_range_kind determine_value_range (tree, wide_int *, wide_int *);
inline bool
range_includes_zero_p (const value_range_base *vr)
{
- return range_includes_p (vr, 0);
+ if (vr->undefined_p ())
+ return false;
+
+ if (vr->varying_p ())
+ return true;
+
+ return vr->may_contain_p (build_zero_cst (vr->type ()));
}
#endif /* GCC_TREE_VRP_H */
diff --git a/gcc/vr-values.c b/gcc/vr-values.c
index e151550d963..3f20c1a6fe8 100644
--- a/gcc/vr-values.c
+++ b/gcc/vr-values.c
@@ -1625,7 +1625,7 @@ compare_range_with_value (enum tree_code comp, value_range *vr, tree val,
return NULL_TREE;
/* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */
- if (value_inside_range (val, vr->min (), vr->max ()) == 1)
+ if (!vr->may_contain_p (val))
return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node;
return NULL_TREE;
